The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 25, 1984
Filed:
Dec. 30, 1982
Vernon D Beck, Ridgefield, CT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Apparatus for compensating for keystone distortion in a flat cathode ray tube in a relatively straightforward and inexpensive manner, and for providing a tube having relatively high resolution and reduced deflection aberration. A magnetic deflection yoke is utilized to scan the raster on the screen, and corrective deflective forces are provided on the electron beam to compensate for keystone. In a first embodiment, the corrective forces are provided by a magnetic hexapole field, in second and third embodiments by magnetic quadrapole fields in series with horizontal and vertical deflections respectively, and in a fourth embodiment by providing the combination of a hexapole field and orthogonal quadrapole field in series with horizontal and vertical deflections respectively.